Hi ,
Dont worry u have to start at somtime, First of be confident , Organise the material u r about to speak in a proper manner.It should have a body of Greetings, abit of self introduction, summary of the Tuition of Orphanage, valuable task achieved, a bit of praise for the same and end up with the thank you. Use a simple and grammatically correct language. Add a bit of humour and light moments. Do not speak in monotous voice add pauses and pitches at the right notes. Best of Luck.
Regards,
Nahela